diff --git a/problems/0104.二叉树的最大深度.md b/problems/0104.二叉树的最大深度.md
index 3eecdc92..2229a854 100644
--- a/problems/0104.二叉树的最大深度.md
+++ b/problems/0104.二叉树的最大深度.md
@@ -523,8 +523,8 @@ func maxdepth(root *treenode) int {
 
 ```javascript
 var maxdepth = function(root) {
-    if (!root) return root
-    return 1 + math.max(maxdepth(root.left), maxdepth(root.right))
+    if (root === null) return 0;
+    return 1 + Math.max(maxdepth(root.left), maxdepth(root.right))
 };
 ```
 
@@ -541,7 +541,7 @@ var maxdepth = function(root) {
     //3. 确定单层逻辑
         let leftdepth=getdepth(node.left);
         let rightdepth=getdepth(node.right);
-        let depth=1+math.max(leftdepth,rightdepth);
+        let depth=1+Math.max(leftdepth,rightdepth);
         return depth;
     }
     return getdepth(root);
@@ -591,7 +591,9 @@ var maxDepth = function(root) {
         count++
         while(size--) {
             let node = queue.shift()
-            node && (queue = [...queue, ...node.children])
+            for (let item of node.children) {
+                item && queue.push(item);
+            }
         }
     }
     return count